Fiber reinforced materials, where the material is commonly a metal, provide a level of strength to a structure that otherwise cannot be attained with just the material itself. The fibers in the material increase the stiffness of the material such that for a given applied load, the material deflects less than an unreinforced material. In order to produce fiber reinforced materials, the fibers are typically bundled together in some fashion and form corresponding to the ultimate devised shape of the fiber reinforced material. Then the material must somehow be forced into the fiber bundle so it completely fills the interstices of the fiber bundle. This is normally accomplished by liquifying the material and then forcing it into the fiber bundle. U.S. Pat. No. 4,573,517 to Booth, et al. discloses an apparatus and method for forcing melted metal into a fiber bundle. It requires the apparatus wherein this method is performed to first be evacuated through a furnace thereof. Then melted metal is forced into a fiber bundle under pressure of gas pumped into the vessel. However, this technique requires, as do all other techniques heretofore known, that the chamber within which the production of the fiber reinforced material occurs be strong enough to withstand the necessary pressures so it does not explode apart either from the inside or the outside. Additionally, in the patent to Booth, the level of melted metal within the structure must be carefully controlled or cooling thereto causes it to solidify making the process useless.
An apparatus is disclosed by Masur, L. J., Mortensen, A., Cornie, J. A. and Flemings, M. C.; "Pressure Casting of Fiber-Reinforced Metals" Proceedings of the Sixth International Conference on Composite Materials ICCM-VI, F. L. Matthews, N. L. R. Bushell, and J. M. Hodginson, Eds. London, 1987, Elsevier Applied Science, pp. 2.320-2.329 wherein a furnace is disposed inside a pressure vessel and pressure alone is used to fill a fiber preform with melted material. However, since this apparatus is for the purpose of determining the pressure necessary to penetrate a fiber preform, usable products therefrom are questionable.
The present invention requires only that a pressure vessel be strong enough to withstand the necessary pressures inside the vessel. As a result, a mold chamber holding a fiber array preform inside the vessel is subject only to small pressure differences, thus allowing much thinner or low strength mold chamber structures. This enables the present invention to be easier to use and quicker to use and enables a more uniform heating of the mold chamber with a single furnace design. Moreover, the level of melted material is not of great concern as long as it fills the mold chamber since cooling of the melted material is actually used for the benefit of the process as opposed to a detriment of the process.